Apparatus for controlling temperature



Jan. 3, 1933. w. EGGLESTON 1,893,277

APPARATUS FOR CONTROLLING TEMPERATURE I Filed March 19, 1950 anvwwozPatented Jan. 3, 1933 UNITED STATES PATENT OFFICE' LEWIS W. EGGLESTON,OF DETROIT, MICHIGAN, ASSIGNOB TO AMERICAN RADIATOR COMPANY, OF NEWYORK, N. Y., A CORPORATION OF NEW JERSEY APPARATUS CONTROLLINGTEMPERATURE Application filed March 19, 1930. Serial No. 437,034.

My invention relates to new and useful improvements in a method andapparatus for controlling or regulating the temperature of a space to berefrigerated or cooled.

An object of my invention is' to provide a method of controlling therefrigerating effect produced by the change of state of a body ofrefrigerant medium and by which it is commercially possible to maintainthe sensible heat of a space to be refrigerated accurately at apredetermined temperature, or accurately between predeterminedtemperature limits.

Another object is to provide an apparatus for performing mynovel'method.

The invention consists in the method and the apparatus for effecting thesame, to be more fully described hereinafter and the novelty of whichwill be particularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of thisspecification, I have fully and clearly illustrated a preferredembodiment of an apparatus for carrying out my novel method, in whichdrawing- Figure 1 is a view in front elevation with the refrigerantcontaining chamber closure member or door removed, and showing atemperature responsive element in vertical com tral section, and

Fig. 2 is a view in vertical central section on the line 2-2 of Fig. 1,but with the door or closure member in place.

Referring to the drawing by characters of reference, 1 designatesgenerally a hollow casing or container member, preferably heat insulatedand having an internal refrigerant medium receiving chamber 2. Themember 1 is preferably rectangular, having substantially solid top,bottom, side and back walls 3, 4, 5 and 6, respectively, and having anopen front provided with V a removable closure member or door 7 whichmay be hinged to the member 1. The walls are preferably of laminatedconstruction, such that the member 1 comprises a frame 8, preferably ofsolid wood, which is encased and sealed in a tin or other light weightmetal jacket 9, and which is lined and externally covered with a heatinsulating material '10, such as cork, or the dimension to fit withinthe wood frame 8, as

in Fig. 2. Within the chamber 2 is a refrigerant medium supporting frameof platform 15, comprising cross-members 16 seated at their ends on basemembers 17-, which in turn rest. on the cork lining 10 ofthe bottom wall4. The member 1 is provided with upper and lower or inlet and outletflow openings or passages 18, 19, respectively, which preferably openthrough the top and bottom walls 3, 4. he top or upper opening 18 isprovided with an upwardly extending conduit member 20, which may beintegral with the jacket 9, but which is preferably separate and sealedthereto by soldering, welding, or the like. Cooperating with and adaptedto seat on the top end of the conduit member 20 1s a valve member ordamper'21, preferably a metal disc, the purpose of which will bedescribed hereinafter. The top wall opening 18 preferably is of steppedconstruction, the frame 8 and lining 10 being eliminated for an areaaround the conduit member 20 (see Fig. 2), so that the temperature ofmember 20 will not drop so low as to cause freezing of valve member 21to member 20. The lower or bottom opening has a depending conduit member22 which may be integral with the jacket 9, but which is preferablyseparate and sealed thereto, as is member 20. The container or casinmember 1 may be supported in any suita 1e manner, as, for example, bylegs or columns 23.

Positioned beneath the member 1 is a heat insulated container or chambermember 24 which is open at its top and which is preferably substantiallyrectan lar. The member 24 preferably has laminated side walls comprisinglayers of wood, tin or other suitable light weight metal, and sheet corkor other insulating material, which are desig nated respectively 25, 26,and 27. The bottom wall 28 of member 24 is preferably of two layers, theinner one 29 being of wood and the outer one 30 being of sheet cork, orthe like, so that the open-topped chamber 31 of member 24 is encased ina jacket of cork or other insulating material. Through the bottom wall28 is a drain outlet 32, preferably formed by a vertical tube of smallinternal diameter and supported in the wall 28. The container member 24is positioned at the proper height to cause the depending conduit member22 to extend partially thereinto, and is of an internal cross area suchthat the member 22 is well spaced from the side walls of member 24 toprovide the necessary flow area between the exterior of the conduitmember 22 and the side walls of member 24, as at 31'. The telescopinglaterally spaced members 22 and 24 comprise a trap for a purpose to bedescribed.

Supported rigidly by the top wall 3 is a bracket member 33 which proects laterally beyond one of the sidewalls 5 and which has at its freeend an upwardly extending arm 34 provided with horizontally spaced earsor lugs 35 extended toward and slightly above the. level of the valvemember 21. Positioned between lugs 35 is one end of a lever arm ormember 36 fulcrumed on a pin 37 passed therethrough and through lugs 35,so that the member 36 is vertically movable. Fixed to the top face ofthe valve member 21 substantially at its center, is a bracket 38,preferably U- haped, which receives the free end of lever member 36.Through alined apertures in the bracket 38 and member 36 is a pin 39which secures the valve member 21 to the lever arm 36. Fixed to anddepending from the arm 36 adjacent its fulcrum is a bearing member 40having in its underface a bearing recess 41 which is preferablysubstantially conical. Depending from the bracket member 33 and spacedlaterally substantially equally from member 40, are depending rigidsupporting rods or members 42. Secured to and supported by the rods 42is a temperature responsive means or thermostat 43, comp'rising a casing43*, within which and hermetically sealing the same is a resilient metalbellows 44 forming an expansion chamber 45 containing a temperatureresponsive liquid, such, for example, as methylchloride. Carried by andmovable with the head 46 of the bellows 44 is a push-rod 47 whichextends upwardly through the bellows i 44 and a guide opening in thebracket member 33 and into engagement with the bearing member 40. Theupper free end of rod 47 is preferably pointed for cooperation with theconical socket or recess 41. The automatic power element 43 and itspush-rod 47 may be steadied against lateral movement by a bracket member48 engagin one of rods 42 and fixed to the casing side wa l 5. The leverarm 36 is preferably provided with a weight member 49 having a set screw50, or the like, and being adjustable longitudinally therealong toregulate the response of the thermostat 43 and therefore the opening andclosing movement of the valve member 21.

The method of controlling the refrigerating effect produced by thechange of state of a mass of refrigerant medium and the operation of theabove described apparatus for performing the method, are as follows: Theabove described apparatus is preferably positioned within an enclosedspace to be cooled or refrigerated, such, for example, as a railwayrefrigerator car, a cold storage room, or a domestic ice box, though itmay be operatively connected to the enclosed space by conduits leadingtherefrom to the upper and lower flow openings. The thermostat controlweight 49 is adjusted on arm 36 to govern the response of the element 43so that the enclosed space will be maintained at or within predeterminedtemperature limits. The door 7 is removed or opened and a body or massof refrigerant medium, designated 51, is placed within the chamber 2 onthe support 15. The refrigerant medium may be a solid, as carbon dioxideice, which is the medium preferably employed, or may be a liquid, thatis, a liquefied gas, such as liquid air or liquid nitrogen, for example,carried in a suitable container. The refrigerant medium having beenplaced within chamber 2, the door 7 is tightly closed. Assuming that theair or gas in the enclosed space to be refrigerated is at a temperatureabove that desired, the thermostat 43 will be expanded so that the valvemember 21 will be open and the temperature within the chamber 2 will beabove that of the refrigerant medium. Due to this state of facts, therefrigerant medium will absorb heat from the gas or air within chamber2, changing the physical state of the medium. The refrigerated or cooledgas within chamber 2 being heavier or of greater density than the gas inthe enclosed space, will pass or drop downward through opening 19 intothe trap or chamber 31, thus drawing higher temperature air or gas fromthe enclosed space into the top of the chamber through the open inletopening 18, and thus continuing to supply chamber 31 which will overflowthrough space 31 into the enclosed space to be refrigerated. There willthus be set up a circulationv of convection gas currents which enterchamber 2 through the opening 18 from the enclosed space, pass downwardin heat absorbing relation to the refrigerant medium 51, issue from theopening 19, and pass through space 31 back into the enclosed space to berefrigerated. As the temperature in the enclosed space drops toward thedesired temperature, the thermostat 43 will permit movement of valvemember 21 toward closed position, thus automatically decreasing theadmission of higher temperature air or gas from the enclosed space tothe chamber 2 and so decreasing the rate of change of physical state ofthe medium 51, resulting in decreasing the refrigerating effect producedby the apparatus. When the temperature of the air or gas in the enclosedspace has reached the predetermined low temperature desired, thethermostat 43 will have caused tight closing of the valve member 21 sothat further entrance of convection gas currents through opening 18 isentirely stopped. The possibility of the valve member 21 freezing fastto the conduit member 20 during this closed period of valve member 21,is efiectively overcome by the stepped construction of passage 18 abovedescribed. With the inlet opening 18 tightly closed, it would seem thatno further change of state of the medium '51 would take p 1ace, but Ihave found that closing of the inlet flow opening 18, when the trap orchamber 31 is not employed, does not in fact stop the change of state ofmedium 51, which therefore results in the temperature of the enclosedspace decreasing below the desired low limit. The trap or chamber 31effectively halts further change of state of the medium 51 bymaintaining within chamber 31 and about the outlet opening 19, anatmosphere or body of refrigerated gas which is substantially at thetemperature of the gas within chamber 2. Since the body of 1refrigerated gas in chamber 31 is of a greater density than that of theenclosed chamberto be refrigerated, the refrigerated gas will pocket inchamber 31 and seal the outlet 19.

This seal of refrigerated gas about the outlet 19 prevents recirculationof gas about the medium 51 from the enclosed refrigerated space into andfrom the outlet 19, which I have discovered would occur save for themaintenance of a body of refrigerated gas about the outlet 19. I havealso found that closing of the outlet opening 19 by valve means isimpracticable, as the very low temperature thereat will cause depositedmoisture from the refrigerated gas or air of the enclosed space tofreeze, thus rendering inoperative mechanical valve devices havingmoving parts. The drain pipe 32 serves to carry off any moisture whichmay collect within chamber 31. and maintains the trap substantially dry.

. What I claim and desire to's ecure by Letters Patent of the UnitedStates is 1. A device of the character described, comprising aninsulated chamber having upper and lower flow openings for thecirculation of convection gas currents through said chamber and adaptedto contain a body of refrigerantmedium, means to close said upper insaid trap.

flow opening operable to maintain about said" lower flow openmg anatmosphere of refrigerated gas whereby to prevent flow of gas into andfrom said chamber through said lower opening.

3. A device of the character described, con1- prising an insulatedchamber having upper and lower flow openings for the circulation ofconvection gas currents through said chamber and adapted to contain abody of refrigerant medium, means to close said upper flow opening, atrap for said lower flow opening operable to maintain about said lowerflow opening an atmosphere of refrigerated gas whereby to prevent flowof gas into and from said chamber through said lower opening, and meansto 4. A device of the character described, comprising an insulatedchamber having upper and lower flow openings for the circulation ofconvection gas currents through said chamber and adapted to contain abody of refrigerant medium, means operable to close said upper flow oening and responsive to temperature of re rigerated gas external to saidchamber, and means at said lower flow opening operable to maintain aboutsaid lower flow opening an atmosphere of refrigerated gas whereby toprevent flow of gas into and from said chamber through said loweropening.

5. A device of the character described, comprising an insulated chamberadapted to contain a body of refrigerant medium and havopening, aconduit mem er depending from the bottom wall of said chamber andopening therethrough into said chamber, and means to maintain an at gasabout the discharge end of said depending conduit member.

6. A device of the character described, comprising an insulated chamber.adapted to contain a body of refrigerant medium and having an upper flowopening, automatic means to close said opening, a conduit memberdepending from the bottom wall of said chamber and opening therethroughinto said chamber, and means to maintain an atmosphere of refri eratedgas about the discharge end of said epending conduit member.

prevent liquid from collecting mosphere of refrigerated 7. A device ofthe character described,

comprising an insulated chamber adapted to contain a body of refrigerantmedium and having an upper flow opening, temperature responsive means toclose said opening, a conduit member depending from the bottom ,wall ofsaid chamber and opening therehaving an upper flow opening, means toclose said opening, a conduit member depending from the bottom wall ofsaid chamber and opening therethrough into said chamber, and

' an open-topped chamber positioned beneath said insulated chamber andinto which said conduit member depends to maintain an atmosphere ofrefrigerated gas about the discharge end of said depending conduit mem-9. A device of the character described, comprisin an insulated chamberadapted to contain a body of refrigerant medium and having an upper flowopening, means to close said opening, a conduit member depending fromthe bottom wall of said chamber and opening therethrough into saidchamber, means to maintain an atmosphere of refrigerated gas about thedischargeend of said; depending conduit member, and means to' preventsealing of said conduit member by liquid.

10. A device of the character described, comprising an insulated chamberadapted to contain a body of refrigerant medium and having an upper flowopening, means to close said opening, a conduit member depending fromthe bottom wall of said chamber and opening therethrough into saidchamber, and means to maintain a body of refrigerated gas about thedischarge end of said depending conduit member, the body of refrigeratedgas being the sole sealing means for said conduit member wherebyrecirculation through said conduit member is prevented when said upperopening is closed.

11. A device of the character described, comprising a, heat insulatedchamber adapted to contain a body of refrigerant medium and havingopenings through its top and bottom walls, a lever member having afulcrum support, valve means carried by said lever member and operableto control flow through said top wall opening, temperature responsivemeans engaging said lever to operate said valve means, a conduit memberextending downward from said bottom wall opening, and a container havingan open top and positioned beneath said chamber, said conduit memberdepending into said container in,

spaced relation to the walls thereof.

12. A device of the character described, comprising a heat insulatedchamber adapted to contain a bodyof refrigerant medium and havingopenings through its top and bottom walls, a lever member having afulcrum support, valve means carried by said lever member and operableto control flow through said top wall opening, temperature responsivemeans engaging said lever to operate said valve means, a conduit memberextending downward from said bottom wall opening, a container having anopen top and positioned beneath said chamber, said conduit memberdepending into said container in spaced relation to the walls thereof,and a drain outlet for said container to drain liquid therefrom.

13'. A device of the character described, comprising a heat insulatedchamber adapted to contain a body of refrigerant medium and havingopenings through its top and bottom walls, a lever member having afulcrum support, valve means carried by said lever member and operableto control flow through said top wall opening, temperature responsivemeans engaging said lever to operate said valve means, a conduit memberextending downward from said bottom wall opening, and a heat insulatedcontainer having an open top and positioned beneath said chamber, saidconduit member depending into said container in spaced relation to thewalls thereof.

In testimony whereof I have hereunto signed my name this 18th day ofMarch, 1930.

LEWIS W. EGGLESTON.

